Chemical composition (nominal) %

Forms of supply

Finishes and dimensions
Sanmac 316/316L bar steel is stocked in a large number of sizes. The standard size range for stock comprises 40-450 mm.
Round bar is supplied in solution annealed and peel turned condition.

Lengths
Bars are delivered in random lengths of 3-7 m, depending on diameter.

Mechanical properties

Bar steel is tested in delivery condition.

At 20°C (68°F)

1 MPa = 1 N/mm²
a) R_p0.2 and R_p1.0 corresponds to 0.2% offset and 1.0% offset yield strength, respectively.
b) Based on L₀ = 5.65ÖS₀ , where L₀ is the original gauge length and S₀ the original cross-section area.

Impact strength

Due to its austenitic microstructure, Sandvik Sanmac 316/316L has very good impact strength both at room temperature and at cryogenic temperatures.

Tests have demonstrated that the steel fulfils the requirements (60 J (44 ft-lb) at -196 ^oC (-320 ^oF)) according to the European standards prEN13445-2(UFPV-2) and EN 10272.

At high temperatures

Physical properties

Relativ magnetic permeability < 2,1
Density: 8.0 g/cm³ , 0.29 lb/in³
Thermal conductivity

Temperature		Temperature
°C	W/m °C	°F	Btu/ft h °F
20	14	68	8
100	15	200	8.5
200	17	400	10
300	18	600	10.5
400	20	800	11.5
500	21	1000	12.5
600	23	1100	13

Specific heat capacity

Temperature		Temperature
°C	J/kg °C	°F	Btu/lb °F
20	485	68	0.11
100	500	200	0.12
200	515	400	0.12
300	525	600	0.13
400	540	800	0.13
500	555	1000	0.13
600	575	1100	0.14

Thermal expansion, mean values in temperature ranges (x10^-6)

Temperature		Temperature
°C	Per °C	°F	Per °F
30-100	16.5	86-200	9.5
30-200	17	86-400	9.5
30-300	17.5	86-600	10
30-400	18	86-800	10
30-500	18	86-1000	10
30-600	18.5	86-1200	10.5
30-700	18.5	86-1400	10.5

Modulus of elasticity, (x10³)

Temperature		Temperature
°C	MPa	°F	ksi
20	200	68	29.0
100	194	200	28.2
200	186	400	26.9
300	179	600	25.8
400	172	800	24.7
500	165	1000	23.5

Corrosion resistance

General corrosion

Sandvik Sanmac 316/316L has good resistance to:

• Organic acids at high concentrations and temperatures, with the exception of formic acid and acids with corrosive contaminants
• Inorganic acids, e.g. phosphoric acid, at moderate concentrations and temperatures, and sulphuric acid below 20% at moderate temperatures. The steel can also be used in sulphuric acid of concentrations above 90% at low temperature.
• E.g. sulphates, sulphides and sulphites
• Caustic environments

Intergranular corrosion

Sandvik Sanmac 316/316L has a low carbon content and therefore good resistance to intergranular corrosion.

Stress corrosion cracking

Austenitic steels are susceptible to stress corrosion cracking. This may occur at temperatures above about 60°C (140°F) if the steel is subjected to tensile stresses and at the same time comes into contact with certain solutions, particularly those containing chlorides. In applications demanding high resistance to stress corrosion cracking, austenitic- ferritic steels, e.g Sanmac 2205 or SAF 2507, have higher resistance to stress corrosion cracking than 316L.

Pitting and crevice corrosion

Resistance to these types of corrosion improves with increasing molybdenum content. Thus, the molybdenum-alloyed Sandvik Sanmac 316L/316L has substantially higher resistance to attack than steels of type AISI 304 and 304L.

Gas corrosion

Sandvik Sanmac 316/316L can be used in

• Air up to 850°C (1560°F)
• Steam up to 750°C (1380°F

Creep behaviour should also be taken into account when using the steel in the creep range. In flue gases containing sulphur, the corrosion resistance is reduced. In such environments the steel can be used at temeratures up to 600–750°C (1110–1380°F) depending on service conditions. Factors to consider are whether the atmosphere is oxidising or reducing, i.e. the oxygen content, and whether impurities such as sodium and vanadium are present.

Heat treatment

Sanmac 316/316L bars are delivered in solution annealed condition.

Solution annealing
1040–1100°C (1900–2010°F), rapid cooling in air or water.

Welding

Suitable welding methods for Sandvik Sanmac 316/316L are manual metal-arc welding (MMA) with covered electrodes and gas-shielded arc welding with the TIG and MIG methods as first choice. Preheating and post-weld heat treatment are normally not necessary.

Due to the fact that this material is alloyed in such a way that it shall have good machinability there can be a higher amount of surface oxides on the weld beads compared to standard 316L steels. This may lead to arc instability during TIG welding, especially at autogenous welding. A correct setting of the welding current is of great importance. However, when filler metal is used, the weldability is the same as for standard 316L steels.

When filler metal is used, Sanmac 316/316L has the same behaviour as standard 316/316L at welding

Since the material has low thermal conductivity and high thermal expansion, welding must be carried out with a low heat input and with welding plans well thought out in advance so that the deformation of the welded joint can be kept under control. If, despite these precautions, it is foreseen that the residual stresses might impair the function of the weldment, we recommend that the entire structure be stress relieved. See recommendations under "Heat treatment".

Recommendations of filler metal:
TIG (GTAW/141) 19.12.3L or 19.12.3LSi
MIG (GMAW/131)         19.12.3L or 19.12.3LSi
MMA (SMAW/111) 19.12.3L , 19.12.3LSi or 19.12.3.LRHD

Applications

Sanmac 316/316L is used for a wide range of industrial applications where steels of type AISI 304/304L have insufficient corrosion resistance.
Typical examples are: Machined parts for tube and pipe fittings, valves, components for pumps, heat exchangers and vessels, different tubular shafts
in chemical, petrochemical, fertilizer, pulp and paper and power industries as well as in the production of pharmaceuticals, foods and beverages.

Industrial categories	Typical applications
Chemical industry	Flanges
Food industry	Valves
Petrochemical industry	Fittings
Pulp & paper industry	Couplings
	Rings
	Seals
	Bolts and Nuts
	Shafts
	Discs